A wide variety of mechanical apparatuses has been developed for use in the mixing of various solids/liquids suspension systems, such as paints and the like. The basic structure employed in the majority of such mixers can generically be described as some form of stirred vessel; i.e., a tank or mixing chamber having one or more mechanically driven agitators or impellers mounted therein. Said agitators can vary widely in type, location and method of mounting in a particular mixing chamber.
When the impeller is not equipped with its own surrounding shroud or stator elements, tank wall baffles are sometimes employed to alter flow patterns therein and promote better mixing. Such baffles are usually uniform, elongated, rigid strips mounted longitudinally in the mixing chamber in a generally axial direction along or near the lateral wall thereof. In the standard arrangement for "fully baffled" cylindrical chambers equipped with concentrically mounted agitators, about four such baffles located at regular (i.e., 90.degree.) intervals around the chamber wall are most often recommended.
Such baffles are usually solid parallelepiped strips (e.g., of metal plate) and are usually oriented so that a small axis thereof is aligned with radii of said chamber. However, it is also known to use slanted mounting of such parallelepiped strip baffles, so that an axis thereof is oriented at an angle to the axis and/or the radii of such chamber. Typical prior art teachings regarding baffle arrangements for mixing devices are found in the following publications:
(1) Chemical Engineering Progress 44, p. 189 et seq., (1948) - article by D. E. Mack & A. E. Kroll;
(2) Chemical Engineering Progress 44, p. 341 et seq., (1948) - article by E. J. Lyons; and
(3) U.S. Pat. No. 2,159,856 - MacLean (1939)
(4) U.S. Pat. No. 2,082,796 - Gaertner (1937)